Centrifugal apparatus for mixing gases and liquids



Oct. 27, 1953 F. J. J. J. HENRARD CENTRIFUGAL. APPARATUS FOR MIXINGGASES AND LIQUIDS 4 Sheets-Sheet l Filed Oct. 4, 1950 v a l Oct. 27,1953 F. J. J. J, HENRARD 2,557,025

CENTRIFUGAL APPARATUS FOR MIXING GASES AND LIQUIDS Filed Oct. 4, 1950 4Sheets-Sheet 2 Jwmw l, jm, A fw@ A fry 3 Oct. 27, 1953 F. J. J. J.HENRARD 2,557,025

CENTRIFUGAL APPARATUS FOR MIXING GASES AND LIQUIDS Filed Oct. 4, 1950 4Sheets-Sheet 3 Oct. 27, 1953 F. 1. J. J. HENRARD 2,657,025

CENTRIFUGAL APPARATUS FOR MIXING GASES AND LIQUIDS Filed Oct. 4, 1950 4Sheets-Sheet 4 Patented Oct. 27, 1953 CENTRIFUGAL APPARATUS FOR MIXINGGASES AND LIQUIDS Fernand Jean Joseph Julien Henrard, Remicourt,

Belgium, assigner to Ecremeuses Melotte, Societe Anonyme, Remicourt,Belgium, a Belgian Company Application October4, 1950, Serial No.188,308 In Luxemburg October 13, 1949 5 Claims.

My present invention relates to 4a centrifuging apparatus comprising arotary vat or cylinder capable of carrying `along a liquid or a mixtureof liquids simultaneously with air, a gas or a mixture of gases in orderto let themsubsequently escape in the form of a sheet or of very thinjets directed against a receiving wall.

In the United States patent application No. 142,866 of February 7, 1950,there has been Adescribed and claimeda process for the separation ofvone or more constituents in suspension in a mother liquor, and moreparticularly of micellae or other particles which may flocculate withina liquid phase.

One of the objects aimed at by the present invention is to provide amachine which is capable of carrying out this process in commercialpractice, but which could likewise `be utilized With respect to otherapplications.

The invention is based on the discovery that in the case of acentrifuging apparatus, the liquid leaving the rotary vat or cylinder,reaches the receiving wall `with a kinetic energy which is composed oftwo components, one of which is perpendicular to said wall and the otheris tangential to the latter at the same point considered.

It is to be noted that the trajectory of the liquid, `which istangential to the discharge circle, increases `in proportion yto theincrease :ci the diameter of discharge of the liquid from the vat if theradial distance between the receiving wall and the discharge circle ofthe liquid is kept constant. Since the path of the liquid increases, itsspreading increases, too, .and consequently at the moment of impactagainst the receiving wall the kinetic energy of the liquid diminishes,and does so the more since one has to take additionally into account thefriction of the liquid in the air or .in the ambient gases.

In other words, `when the trajectory grows, the unit mass of liquid `aswell as the velocity of the liquid diminish; hence a decrease in thekinetic energy which has been imparted initially on the liquid.

`In order to preserve to the liquid or to the liquid-gas mixture at themoment of impact the Vor (Figure 6) included between the trajectory (rtlor t2) of the liquid `or of the `mixture of liquid and gas emerging.from the vat at any point of @lo the discharge circle C1 or C2 and thetangent ta to the receiving circle Ca at the corresponding theoreticalpoint of impact increases the more, the more the `circle of dischargefrom the vat approaches the circles of the impact Ca (angle being largerthan angle a) so as to become theo retically eventually equal to 180,for which angle the two tangents are in alignment with one another. Inorder to place the angles in question hereinabove correctly, `oneconsiders those of the angles as positive which are included between thetrajectories (t1-or t2) of the liquid and the tangent tR to thereceiving circle CR in the portion of the latter, the `sense of whichcorresponds to the sense of rotation of the vat or cylinder.

At the theoretical point of impact this kinetic energy can be resolvedinto two components: one perpendicular to the receiving circle, and theother tangential at the same point of the circle.

These two lcomponents are perpendicular to one another.

The component in the direction of the tangent to the receiving circledetermines naturally a spiral movement of rotation of the liquid on thereceiving circle whereas the other component corresponds to the desiredkinetic energy of impact,

It need not be demonstrated that this impact would `be a maximum if thereceiving wall were perpendicular to the trajectory of emergence of theliquid and if the spreading of the said liquid were reduced to zero:provided, that the velocity of the liquid at the moment of its receptionwere equal to that which -it had acquired at the moment of its leavingthe vat (apart from the resistance to its displacement in the medium).

These conditions cannot be fulfilled if the receiving circle isconstituted by a circular crown concentric to the circle of emergenceofthe liquid, whatever be the distance provided between said circularcrown of reception and the circle of discharge of the liquid from thevat.

Therefore in order to attain outputs of commercial value, it isnecessary to arrange it sothat the impact `takes place in conditions asperfect as possible.

To this effect a series of impact surfaces designed to receive the sheetof liquid emerging from the vat or cylinder in rotation is arrangedaccording to the invention at the level of the discharge edge of the vator of the cylinder and completely surrounding the same. These surfacesare disposed perpendicular or .substantial- 1y perpendicular to thetrajectories which are followed by the liquid or mixture of liquid andgas emerging tangentially from the vat or cylinder in rotation,

Moreover, these annularly arranged impact surfaces are placed as near aspossible to the vat or cylinder in order to obviate any appreciable lossof the kinetic energy initially imported to Y the liquid.

In order that the invention may be well understood, an apparatusconstructed in accordance with the invention will now be described byway of example but not of limitation.

Figure 1 is a view in vertical section showing the rotary vat and itsdriving device. This embodiment is purely by way of example, for asimilar apparatus could be easily conceived which would have a bell, theopening of which would be turned for example upward.

Figure 2 is a plan view of a detail representing the top portion of amushroom xed to the vat.

Figure 3 is a view in vertical section representing the assembly of theapparatus.

Figure 4 represents a plan view of the impact device receiving theliquid at its exit from the vat.

Figure 5 relates to a modification of this device in which the number ofreceiving buckets has been increased, which number varies according totheapplications.

Figure 6 is a diagram showing of the liquidY or mixture emerging fromrespective points of discharge.

An apparatus constructed according to the invention comprises a rotaryvat or cylinder which functions to carry along the liquid, and todisperse it, and which in this embodiment is supplied with raw liquidfrom the top by means of an entrance orifice 2 from a fixed piece 2.This supply could alternatively be effected in a different way. Thiselement I is arranged at the interior of a fixed envelope 3 (Figure 3),which forms the base and, in the embodiment represented, is assumed tobe cylindrical. It can nevertheless have any other appropriate shape.

The upper portion of the rotary cylinder is made in the shape of a bellI', and below said bell there is fixed, for example by means of screwbolts 4 and of Vdov/'els 5 (Figure l), a mushroom 6 which carries apiece of a shaft 'I extending vertically downwards and rotating in ballbearings or others 8 in a sleeve 9 which is made integral, for exampleby means of screw bolts I0, with a tubular support II connected with theinclined bottom I3 of the enevelope 3 by ribs I2 (Figures 1 and 3).

On the sleeve 9 is attached downwardly, for example by screw bolts I4, apiece I5 forming the support for the bearings of the shaft 1.

The vat I can be driven directly, but alternatively it can be driven,according to this embodn ment, by means of a belt I6 running in a grooveI1 formed in the bell I (Figures l and 3).

On the upper face of the mushroom 6 and between said mushroom and thebell of the vat, there is provided an appropriate number of vanes I9(Figures l, 2, an-d 3) which serve as stays between the mushroom 6 andthe bell I of the cylinder I and which serves for carrying along theliquid towards the periphery of the cylinder I and for sucking insimultaneously air or `a gas which acquires likewiseV the angularvelocity of the vat. I

As will be readily understood, the liquid introduced at 2 falls on tothe mushroom 6, and 1s carried along owing to the fact that the assemblyI--I-l and I9 is in rotation.

the trajectories the vat at On the other hand, the vanes I9 areconstructed in such a manner that when the liquid has left them, theliquid turns at the velocity of the inner wall of the vat and thenspreads out over the inner cylindrical portion of the vat from where iteventually escapes in a thin and uniform sheet.

The liquid emerges at the lower portion of this cylinder, and forms bycentrifugal action a practically horizontal sheet or layer which isprojected outwards.

An essential feature of the apparatus consists in that the sheet ofliquid that emerges from the cylinder l is received on a series ofimpact surfaces 2I (Figure 4) which are disposed perpendicularly oralmost perpendicularly to the tangential trajectory the liquid takesafter its emergence from the cylinder I.

An important condition is that the surfaces be sufficiently close to thecylinder in order to prevent la subsequent loss of the kinetic energyimparted to the liquid.

From the point of view of construction, the surfaces 2I are usuallyconnected with one another by connecting surfaces 22 which prevent anysplashing towards the exterior.

These surfaces 2I and 22 cooperate also with one another in formingbuckets 23 each of which receives part of the liquid, and which possesspreferably a third face 2drwhich is disposed parallel or almost parallelto the tangential trajectory of the liquid and which prevents anysplashing towards the vat. Y

These surfaces 24 terminate in general in a chamfer 25 intended toprevent a subsequent impact from already occurring at the edges of thesesurfaces 24 which would cause part of the liquid to rebound onto thevat. The buckets formed by the surfaces 2I and 22 abut at 21 on a crown26 which is disposed, substantially edgewise, concentrically to thecylinder I (Figures 3 and 4).

It is, however, important that this abutment be arranged, as shown inthe drawing (Figure 4), outside the trajectory of the jet of liquidreceived in the bucket and that thus a neutral zone 23' is formed whichdoes not receive any liquid. Thus it is made certain that the wholesheet of liquid meets the surface 2l in directions which areperpendicular or almost perpendicular to this surface.

The crown 26 is, in this embodiment, represented as fixed to thestructure by means of screw bolts 28 (Figure 3) which traverse the wallof the envelope 3 in a horizontal direction and extend through sleeves29; but any other manner of fixation may alternatively be employed.

A flat ring 30 is moreover provided which comes into Contact with theupper edges of the crown 26 and of the pieces 2I-22-2ll which composethe assembly of the impact device.

In this manner any projection of the liquid upward is obviated.

The mixture of liquid and air, after having hit the surfaces 2|, escapesdownwardly, meets the bottom I3, and is discharged by the exit orifice3|.

Figure 5 relates to a modication'of the embodiment in which the numberof buckets 23 has been increased. It will be seen that in this case thelength of the surfaces 24 has to be increased in a corresponding manner.

Numerous modifications of construction can be applied with respect towhat has been described hereinabove and represented in the drawings.

Thus notably the impact device could be limited to a series of surfaces2l xed in an appropriate manner in the position shown, and an apparatusconstructed in this manner would evidently not fall outside the scope ofthe invention.

The apparatus forming the subject of the invention iinds its applicationnotably with a view of carrying into practice the process described andclaimed in the United States patent application Ser. No. 142,866 filedFebruary 7, 1950, and relating to the separation of one or severalconstituents in suspension in a liquid, which process is characterisedin that the micellae or particles which may flocculate within a liquidphase are placed into such conditions as are suitable for fixing air, agas or a mixture of gases and thus to acquire eventually a buoyancyforce sufficient for causing a rapid separation of the micellae or otherparticles, and for causing a concentration on the surface of the liquid,or a sedimentation, of a constituent of a density initially equal to ahigher value than that of the liquid, while the latter becomes graduallyclear.

When the apparatus described is used for this purpose, the liquid to betreated and containing the constituents to be separated is introduced at2 at the same time as the air or other gas which is sucked in by thevanes I9; the liquid and the air, which leave the vat l, escape in theform of laminations or jets which are sufficiently thin to ensure anintimate contact of the air or of the gas with the particles, and tosecure the fixation of the air or of the gas to the micellae. The excessof this air or of this gas escapes eventually with the liquid, takingpart, as explained in the prior United States patent application, in theformation of the sedimentation.

It is, however, well understood that the ambit of protection of thepresent patent is by no means limited to this application, and that thesame apparatus nds use with a view of treating liquids or mixtures ofliquids by this kind of centrifuging.

It can be particularly employed to effect, by the means described, themixing of several liquids or of one or several liquids with one orseveral gases.

What I claim is:

1. Centrifugal apparatus for dispersing and mixing a gas and a liquid,including a cylinder and means for rotating the same, means foradmitting a liquid into said cylinder, means for spreading the liquidalong the inner periphery of the cylinder whereby the liquid escapes asa sheet in a tangential trajectory from the lower cylinder edge, meansfor sucking air into said cylinder, means for mixing said air with saidliquid and a series of impact surfaces positioned along the lowerportion of the cylinder' and extending substantially perpendicular tosaid trajectory, said trajectory being followed by both air and liquid,said impact surfaces being positioned sufficiently close to the loweredge of the cylinder, so as to obviate a subsequent loss of the kineticenergy of the mixture, and also being located in a staggered relation soto be substantially perpendicular to the trajectory followed by thesheet of air and liquid and are located sufficiently close to the loweredge of the cylinder, so as to obviate a subsequent loss of the kineticenergy of the mixture, connecting surfaces and also including means forconnecting with one another the impact surfaces, whereby to prevent thesplashing of the mixture towards the exterior, and said connectingsurfaces together with the impact surfaces forming buckets, each ofwhich receives a part of the mixture.

2. Centrifugal apparatus according to claim l, in which each bucketincludes a third face arranged substantially parallel to the trajectoryof the mixture, so as to prevent any splashing towards the cylinder.

3. Centrifugal apparatus according to claim 1, also including a crownwhich is disposed substantially edge-wise and concentrically to saidcylinder, and on which said buckets abut.

4. Centrifugal apparatus according to claim 3, in which said bucketsabut said crown in regions where each` active impact surface isconnected t0 a corresponding connecting surface.

5. Centrifugal apparatus according to claim 4, in which the connectionbetween an impact surface and a connecting surface takes place towardsthe exterior in a region situated outside the trajectory of the sheetreceived in the bucket, whereby the whole sheet may always meet theimpact surface at an angle of impact which is substantiallyperpendicular to it.

FERNAND JEAN JOSEPH JULIEN HENRARD.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 628,092 Hepburn July 4, 1899 1,267,166 Bahnson May 21, 19182,163,474 Sloan June 20, 1939 2,220,574 Little Nov. 5, 1940 FOREIGNPATENTS Number Country Date 29,844 Switzerland Mar. 4, 1903 180,035Germany Mar. 4, 1903

